Darmon M, Barra J, Brachet P
J Cell Sci. 1978 Jun;31:233-43. doi: 10.1242/jcs.31.1.233.
The role of cAMP phosphodiesterase in the cAMP-mediated aggregation of the cellular slime mould Dictyostelium discoideum was investigated with a morphogenetic mutant defective in phosphodiesterase production. Mutant cells become capable of aggregating normally when incubated in the presence of exogenous phosphodiesterase isolated from Idictyostelium or rat brain. Direct contact between enzyme and the cell membrane is not required for this phenotypic suppression. The aggregateless character of this strain presumably results from an over-accumulation of cAMP in the extracellular medium since aggregation can be induced in the absence of added phosphodiesterase under conditions facilitating diffusion of the nucleotide. This suggests that phosphodiesterase is not involved in the generation or recognition of cAMP signals, but that the enzyme is essential in the control of the cAMP signal-to-noise ratio.
利用一种在磷酸二酯酶产生方面存在缺陷的形态发生突变体，研究了环磷酸腺苷（cAMP）磷酸二酯酶在细胞黏菌盘基网柄菌cAMP介导的聚集过程中的作用。当在从盘基网柄菌或大鼠脑中分离出的外源性磷酸二酯酶存在的情况下孵育时，突变细胞能够正常聚集。这种表型抑制不需要酶与细胞膜直接接触。该菌株的不聚集特性可能是由于细胞外培养基中cAMP的过度积累所致，因为在促进核苷酸扩散的条件下，在不添加磷酸二酯酶的情况下也可以诱导聚集。这表明磷酸二酯酶不参与cAMP信号的产生或识别，但该酶对于控制cAMP的信噪比至关重要。
